Messages in this thread | | | Date | Fri, 11 Mar 2022 19:38:15 +0100 | Subject | Re: [PATCH 2/2] PCI/PM: Fix pci_pm_suspend_noirq() to disable PTM | From | "Rafael J. Wysocki" <> |
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On 2/24/2022 9:29 PM, Rajvi Jingar wrote: > For the PCIe devices (like nvme) that do not go into D3 state still need to > disable PTM on PCIe root ports to allow the port to enter a lower-power PM > state and the SoC to reach a lower-power idle state as a whole. Move the > pci_disable_ptm() out of pci_prepare_to_sleep() as this code path is not > followed for devices that do not go into D3. This patch fixes the issue > seen on Dell XPS 9300 with Ice Lake CPU and Dell Precision 5530 with Coffee > Lake CPU platforms to get improved residency in low power idle states. > > Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com> > Suggested-by: David E. Box <david.e.box@linux.intel.com>
I would add a Fixes tag pointing to the commit that introduced pci_disable_ptm().
Otherwise I agree with this change:
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> --- > drivers/pci/pci-driver.c | 11 +++++++++++ > drivers/pci/pci.c | 10 ---------- > 2 files changed, 11 insertions(+), 10 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index ac3f7e1676a9..8be3f81afdf6 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -836,6 +836,17 @@ static int pci_pm_suspend_noirq(struct device *dev) > > if (!pci_dev->state_saved) { > pci_save_state(pci_dev); > + > + /* > + * There are systems (for example, Intel mobile chips since Coffee > + * Lake) where the power drawn while suspended can be significantly > + * reduced by disabling PTM on PCIe root ports as this allows the > + * port to enter a lower-power PM state and the SoC to reach a > + * lower-power idle state as a whole. > + */ > + if (pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT) > + pci_disable_ptm(pci_dev); > + > if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev)) > pci_prepare_to_sleep(pci_dev); > } > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 9ecce435fb3f..f8768672c064 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -2660,16 +2660,6 @@ int pci_prepare_to_sleep(struct pci_dev *dev) > if (target_state == PCI_POWER_ERROR) > return -EIO; > > - /* > - * There are systems (for example, Intel mobile chips since Coffee > - * Lake) where the power drawn while suspended can be significantly > - * reduced by disabling PTM on PCIe root ports as this allows the > - * port to enter a lower-power PM state and the SoC to reach a > - * lower-power idle state as a whole. > - */ > - if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) > - pci_disable_ptm(dev); > - > pci_enable_wake(dev, target_state, wakeup); > > error = pci_set_power_state(dev, target_state);
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